High energy impact wrench assembly

ABSTRACT

A wrench assembly operated by a high energy impact for use on large nuts or bolts. The assembly includes a heavy housing and a lever mounted for limited rotation within the housing. Gripping means for engaging and transmitting torque to the nuts or bolts project outwardly of the housing from the axis of rotation of the lever. The tang of the lever is located adjacent an opening in the top wall of the housing so that a power hammer can be positioned over the opening to impart blows through the opening to the tang and to transmit high turning forces to the gripping means.

United States Patent Berg [ 51 July 11, 1972 [54] HIGH ENERGY IMPACTWRENCH ASSEMBLY [72] inventor: Louis L. Berg, Denham Springs, La.

[73] Assignee: Creative Tool Company, Denham Springs,

22 Filed: Sept.30, 1970 [21] Appl.No.: 76,731

[52] U.S.Cl ..8l/I21,8l/52.3 [5 I] Int. Cl. ..B25b 13/06, B25b 19/00[58] Fleldolseanch ..8 l/S2.3, 52.35, 57.39, 57.46,

[56] References Cited UNITED STATES PATENTS 3.273.428 9/1966 Rudeke..8l/52.3

3,272,035 9/l966 Ekstrom et a] .......8l/52.3 3,21 [.028 l0/l965Christensson... ..8l/52.3 3,l24,022 3/l964 Carson ..8l/57.29

Prima -y Examiner-James L. Jones, Jr. Attorney-Firmcgan, Henderson,Farabow and Garrett ABSTRACT A wrench assembly operated by a high energyimpact for use on large nuts or bolts. The assembly includes a heavyhousing and a lever mounted for limited rotation within the housing.Gripping means for engaging and transmitting torque to the nuts or boltsproject outwardly of the housing from the axis of rotation of the lever.The tang of the lever is located adjacentanopeninginthetopwailofthehousingsothatapower hammer can be positionedover the opening to impart blows through the opening to the tang and totransmit high turning forces to the gripping means.

PATENTEDJuL 1 I m2 sum 1 or 2 "wan-r0:

LOUIS L. BERG 1 HIGH ENERGY IMPACT WRENCH ASSEMBLY This inventionrelates to impact driven wrenches and more particularly to a simplifiedwrench assembly operated by a high energy impact for loosening ortightening very large nuts or bolts and for turning very large valves.

Large nuts, bolts and the like are used in a variety of applicationsincluding, for example, the joining or fastening of access flanges,covers and housings commonly associated with high temperature hirnaces,boilers, turbines, compressors, or steam and internal combustionengines. Other applications include earthmoving and dredging machinery,structural frame members, oil field refinery and mining equipment, pipelines, railroad equipment and machinery, ships engines and components,manufacturing plant equipment, metal working machinery and many othertypes of large machinery and equipment.

Nuts, bolts, and other threaded members when used in these and otherapplications are normally left in place for long periods of time, and inmost cases, they are subjected to extreme environmental conditions, suchas intense heat, corrosive atmospheres, oxidation, electrolysis,rusting, scaling, deformation by stress and the like.

Removal of such large nuts and bolts requires exceptionally large rotarytorque forces. Often a two-step process has been required to loosenthese large nuts or bolts. The first step is to break the bond betweenthe nut and the bolt created by its exposure to the extreme conditionsand the second step is to complete the removal by use of conventionalimpact wrenches operated with air, fluid, or by an electrical or otherpower source. In most instances in which nuts and bolts are particularlydifflcult to remove or loosen, the nuts and bolts are first loosened bymanually applying impacts against rugged hammer wrenches. In many cases,continuous hammer blows against the wrenches are required for hours oreven days be fore there is a break and an apparent loosening of the nutor bolt.

In the past, various types of power impact driven wrenches have beenused, but these wrenches have often proved ineffective because of thelarge sizes of the nuts or bolts and because of the extremely highbonding forces that exist between the threaded members resisting themaximum force-imparting capability of the power source. Further, suchpower impact wrenches are usually constructed of many operating partsand employ various mechanical linkages making them susceptible tobreakage and failure under heavy use.

ln accordance with the present invention, a safe, simple, rugged andvery versatile wrench assembly is provided for use with high energylinear impact driving means to produce exceptionally high rotary torque.The assembly comprises a housing having a pair of opposed parallel sidewalls with coaxially aligned first and second bores. An opening isfurther provided in a first end of the top wall of the housing.

A unitary lever member is rotatably mounted within the housing, saidlever member including a first relatively large body portion locatedbetween the side walls of the housing, a pair of cylindrical shoulderportions integral with and on either side of the large body portion, anda tang integral with the large body portion and extending radiallyoutwardly from the axis of the shoulder portions. The cylindricalshoulder portions are journaled within the side wall bores, and therelatively large body portion has at least one dimension greater thanthe diameters of the bores to permit rotary movement while substantiallypreventing axial movement of the lever member within the housing. Thetang also is located adjacent the opening in the top wall of thehousing.

In accordance with the invention, nut gripping means are furtherprovided that project outwardly of the housing from a first one of theshoulder portions of the lever member in coaxial relationship with thebores whereby power hammer means can be positioned adjacent the openingin the top wall of the housing to impart linear blows through theopening to the tang and to provide high turning forces to the grippingmeans.

tegral with and extending outwardly from the shoulder portionandhsvinganutengagingportin itsouterfaceforgripping the nut or bolt.Alternatively, the nut gripping means comprise an extension integralwith and extending outwardly from the shoulder portion and an annularsocket that is removably mounted to the extension.

In accordance with a preferred embodiment of this invention, nutgripping means also project outwardly from the second shoulder portionof the lever member and in co-axial relationship with the bores so theassembly can be used to both tighten or loosen nuts or bolts.Alternatively, one of the side walls of the housing is removable topermit removal and reversal of the lever member within the housing sothat the wrench assembly can be used to either tighten or loosen thenuts or bolts.

Resilient means are also preferably provided within the housing forreceiving the tang aher each impact and for absorbing at least a portionof the energy impacted to the tang by the power hammer means.

The invention thus uses a minimum number of heavy and sturdy parts toprovide a safe, reliable, efficient and very rugged device fortightening or loosening very large nuts or bolts.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory onlyand are not restrictive of the invention.

In the drawings:

FIG. I is a perspective view of the wrench assembly of this invention;

FIG. 2 is a top view partially in section of the assembly shown in FIG.1 with the socket removed for clarity.

FIG. 3 is a broken sectional view taken along the line 3-3 of FIG. 2;

FIG. 4 is a fragmentary section of a portion of the assemblyillustrating its relationship with a power hammer; and

FIG. 5 is a sectional view similar to FIG. 3 and showing anotherembodiment of the invention.

With reference now to the drawings, wherein like reference charactersdesignate like or corresponding parts throughout the several views,there is shown in FIG. I an embodiment of the invention which includes aheavy encasement or housing I0. The housing is preferably made of heavysteel plate and is generally rectangular in shape. The housing has twoopposed parallel side walls 12 and 14 having co-axially aligned firstand second bores 16 and 18, a top wall 20 having an opening 22 adjacenta first end of the top wall, and a bottom wall 23.

In accordance with this invention, a unitary lever member, generally 25is mounted within the housing. As embodied, and as best shown in FIG. 2and 3, a lever member 25 has a first relatively large body portion 24positioned closely adjacent the inside of side walls 12 and I4 andbetween side wall bores 16 and 18. Body portion 24 of the lever memberis preferably cylindrical in shape and has a diameter greater than thediameters of bores 16 and 18 to prevent any substantial movement of thelever member and body portion 24 along the axis of the bores. Althoughthe body portion of the lever member is preferably cylindrical, it mayalso be square, triangular, or of other shape without departing from theprinciple of the invention. However, body portion 24 must have an outerdimension sufficient to permit it to rotate within housing 10 andwithout interference with the top and bottom walls of the housing.

The lever member also includes a pair of cylindrical shoulder portions26 and 28 integral with and on either side of body portion 24 andjournaled within bores 16 and I8, respectively, of the side walls of thehousing. These shoulder portions are characterized by diameterssubstantially equal to but smaller than the respective diameters ofbores 16 and 18 to permit the shoulder portions to rotate within thebores.

Although shoulder portions 26 and 28 of the lever member are shownjoumaled within bores 16 and 18, respectively, preferably the shouldersand bores are similar in size to permit tnrrux arr.

reversal of the lever member within housing so that shoulder portion 26can be journaled within bore 18 and shoulder portion 28 can be journaledwithin bore 16. This provides the wrench assembly with the desirablefeature of being able to tighten as well as loosen nuts or bolts and aswill be more fully explained below.

In accordance with this invention, nut gripping means are provided thatproject outwardly from one of the shoulders of the lever member forengaging and transmitting torque to a nut or bolt in response tooperation of the wrench assembly. As embodied and as shown in FIG. 2,the gripping means comprise a relatively small sized extension 30 thatis integral with shoulder 26 and extends outwardly in a co-axialdirection with the axis of bores 16 and 18. Extension 30 may take avariety of forms. Preferably, the extension remains small enough to passthrough both bores 16 and 18 so the reversible feature of the wrenchassembly is maintained, and the assembly can be used for eithertightening or loosening nuts or bolts.

Extension 30 may, for example, be shaped for use with a removable socket31 as shown in FIG. 1. This embodiment is best illustrated in FIGS. 2and 3 where extension 30 is of square cross section for rotationalconnection with socket 3].

In another embodiment of the invention as shown in FIG 5, extension 30is itself shaped to engage the nuts and bolts. In this embodiment theextension has a hexagonal port 32 in its outer face so the extension canbe placed directly over the not or bolt to be tightened or loosened.

Clearly, numerous other shapes and configurations could be used forextension 30 in accordance with the invention such as one of hexagonalcross section whereby the wrench assembly could be used with Allenhead-type bolts.

In accordance with the invention, a tang or shank 34 forms an integralpart of the lever member and extends from body 24 in a radial directionwith respect to the axis 35 of bores 16 and I8. The tang defines twosubstantially congruent faces 36 and 38, and the lever member ispositioned within the housing such that when rotated to the top of itstravel in the encasement, face 36 of tang 34 is located adjacent to andin substantially parallel relationship with the inside of top wall 20and opening 22.

Power hammer means 48, partially illustrated in FIG. 4, can then bepositioned adjacent opening 22 to impart a linear blow to tang 34through the top wall opening to provide high rotational forces to thelever member and the nut gripping means, whereby the nut or bolt istightened or loosened as desired.

In accordance with a preferred embodiment of the invention and as shownin FIG. 2, second nut gripping means are provided comprising a secondrelatively small sized extension 40 that projects outwardly fromshoulder 28 in co-axial relationship with bores 16 and I8 and which issimilar in shape to extension 30. Such an embodiment provides theadvantage of enabling the wrench assembly to be used for both looseningand tightening without requiring that the lever member be removed fromthe encasement.

Further, extension 40 can be used as an anvil by providing a flatsurface 41 for receiving impacts from a manual or power hammer to forcethe gripping means on extension 30 into position around a nut or into anannular socket wrench attachment.

Alternatively, and as shown in phantom in FIG. 2, extension 40' can havea threaded end 42 for securing any desired attachments to assembly suchas an anvil cap or power impact means.

Housing 10 also includes a bottom wall 23, and in accordance with theinvention resilient means are provided in contiguous relationship withat least a portion of the bottom side for receiving the tang and forabsorbing at least a portion of the force of the tang as it moves inresponse to blows from the power hammer means. As here embodied, and asshown in FIG. 3, the resilient means is a damping plate 46 which islocated beneath tang 34 and beneath hole 22 for damping theexceptionally large linear force created by downward move ment of thetang afier having been impacted by the power hammer. The damping plateprovides an important safety factor by reducing rapid rotation of theencasement in response to the hiflr energy downward movement of thetang. Thus, the wrench assembly is safe to use and injuries to theoperator are minimized. The large man ofthe encasement is also animportant feature, and its high inertia reduces any rapid rotation ofthe encasement as a result of downward strokes of the tang. Further theencasement completely encloses the tang preventing any particles thatmight break off the tang from striking personnel during operation of thedevice.

With reference now to FIG. 4, there is shown the tip of a conventionalpower hammer means 48 positioned adjacent the top side of opening 22 andadjacent tang 34 of the lever member. In accordance with a preferredembodiment of the invention, locking means are provided for receivingand holding power hammer 48 in position to impart blows to the tangthrough top wall opening 22. As embodied and as shown in FIG. 4, thelocking means comprise a plurality of lugs 50 spaced about the innersurface of opening 22 and matable with a plurality of corresponding lugs52 spaced about the outer surface of the end of hammer 48 so that thehammer can be inserted into hole 22 with lugs 52 passing down betweenlugs 50. The hammer is then rotated a quarter turn to engage the lugs asshown in FIG. 4 and to hold the hammer in position closely adjacent totang 34.

In operation of the wrench aaembly in loosening nuts or bolts, the levermember is positioned within housing 10, as illustrated in FIG. I. Thewrench assembly is then manipulated so that the gripping means onextension 30 is placed in position over the nut or bolt. Power hammer 48is inserted into hole 22 and is locked into position by lugs 52 and 50.The operator then uses the power hammer as a handle and rotates housing10 as far as possible until face 36 of tang 34 contacts the inside oftop wall 20 of the housing. Tang 34 is, thus, positioned immediatelyadjacent to power hammer 48.

The power hammer is then actuated in a conventional manner to send aplunger 56 against face 36 of tang 34 causing the tang to movedownwardly and in a counterclockwise direction about the axis of bores16 and 18. This movement of the tang exerts a rotary force on body 24which in turn transmits the required loosening torque to the nut orbolt.

As tang 34 moves downwardly, it is received by damping plate 46 whichabsorbs at least some of the force of the tang as it moves in responseto the blow from the hammer. Housing [0 is also preferably formed ofheavy steel or other suitable heavy materials to provide a large massand thereby furnish inertial braking to the forces transmitted to thehousing by tang 34 as it strikes damping plate 46. Thus, the combinationof damping plate 46 together with inertial braking of the heavy housingprevents the wrench assembly from spinning out of control in response tothe hammer blow, making the assembly safer to use and minimizing thedanger of injury to the operator. The cycle is then repeated until thedesired loosening of the nut or bolt is accomplished.

When a nut or bolt is to be tightened, it is first tightened manually orby conventional power driven means until resistance overcomes thecapabilities provided by such devices. When the wrench assembly isconstructed in accordance with a preferred embodiment with bothextensions 30 and 40 having nut gripping means, the whole wrenchassembly is merely turned over so that the gripping means on extension40 is placed in position over the bolt or nut. The same steps asoutlined above for loosening nuts or bolts are then followed with thetang moving clockwise until the desired tightening of the nut or bolt isaccomplished.

When the bolt or nut is to be tightened and lever member 25 has nutgripping means only on extension 30, side wall 14 is removed by removingscrews 54 (FIG. 2) and lever member 25 is removed and reversed in thehousing so that face 38 of tang 34 now lies adjacent the opening 22 inthe housing. Thus, when the tang is hit by the power hammer means, itwill rotate clockwise tightening the nut or bolt.

Imam M Alternatively, to tighten a nut or bolt a second opening 56 maybe provided in bottom wall 23 of housing opposite opening 22. The wrenchassembly is then manipulated so that the gripping means on extension 30is in position over the nut or bolt. The power hammer is then insertedinto opening 56 and the housing rotated until the face 38 of tang 34 isadjacent the inside surface of bottom wall 23. Thus, an impact from thepower hammer causes tang 34 and extension 30 to rotate in a clockwisedirection to tighten the nut or bolt.

The invention thus provides a simply constructed and massive wrenchassembly for use with power hammer means to loosen or tighten very largenuts or bolts.

The invention in its broader aspects is not limited to the specificdetails shown and described and departures may be made from such detailswithout departing from the principles of the invention and withoutsacrificing its chief advantages.

What is claimed is:

l. A wrench assembly operated by high energy impacts including poweroperated hammer means comprising:

a housing having two opposed parallel side walls with axially alignedbores adjacent one end of the housing and opposed, parallel top andbottom walls, said top wall having an opening therein spaced from thebores and adjacent the opposite end of the housing;

a unitary lever member rotatably mounted within the housing about theaxis of the bores for rotational movement between the top and bottomwalls, said lever member having a relatively large body portion locatedbetween the side walls and adjacent the top and bottom walls and havingat least one dimension greater than the diameters of said bores;

a pair of cylindrical shoulder portions integral with and on either sideof the large body portion, said shoulder being journaled within saidbores;

a tang extending radially outward from the axis of the large bodyportion, said tang having a pair of faces converging outwardly from thelarge body portion toward an outer end and shaped to lie adjacent to andin substantially arallel relationship with the inside of either the topor bottom wall when the lever is rotated within the housing, said outerend of the tang being located adjacent the opening in the top wall inoperative position; and

nut-gripping means projecting outwardly of the housing from a first oneof said shoulder portions in co-axial relationship with the boreswhereby power hammer means operating through the opening in the top wallimparts unrestricted, high-energy turning forces to the gripping means,said bottom wall limiting movement of the lever member to a shortrotational distance within the housing substantially equal to theangular relationship between the two converging faces of the tang andsubstantially absorbing the energy from the power hammer meanstransmitted to the lever member.

2. The wrench assembly of claim 1, including nut gripping means alsoprojecting outwardly of the housing from the second one of said shoulderportions in co-axisl relationship with said bores.

3. The wrench assembly of claim 1, wherein said housing includesresilient means contiguous with at least a portion of the inside of saidbottom that receives the tang and for absorbing at least some of theforce of said tang as it moves in response to blows from the powerhammer means.

4. 'Ihe wrench assembly of claim 1, wherein one of said side walls isremovably aflixed to the housing and the lever member is reversiblewithin the housing to permit the assembly to be used in nut-tighteningor loosening positions.

5. The wrench assembly of claim 1, including a second opening in thebottom wall of the housing opposite said first opening to permit theassembly to be used in nut-tightenin g or loosening positions.

6. The wrench assembly of claim 1, wherein said nutgripping meansincludes an extension integral with said first shoulder and having anut-engagin port in its outer face.

7. The wrench assembly 0 catm 1, wherein said nutgripping means includesan extension integral with said first shoulder and having a crosssection compatible with an annular socket wrench attachment.

8. The wrench assembly of claim 1, further including locking means insaid top wall opening for receiving and locking the power hammer meansin position.

9. The wrench assembly of claim 8, wherein the locking means comprises aplurality of matahle lugs on the power hammer means and in the top wallopening.

10. The wrench assembly of claim I, wherein the width of the tangoccupies a substantial portion of the distance between the parallel sidewalls of the housing.

11. The wrench assembly of claim 1, including end walls to provide acompletely enclosed box-like housing.

# Q i i i

1. A wrench assembly operated by high energy impacts including poweroperated hammer means comprising: a housing having two opposed parallelside walls with axially aligned bores adjacent one end of the housingand opposed, parallel top and bottom walls, said top wall having anopening therein spaced from the bores and adjacent the opposite end ofthe housing; a unitary lever member rotatably mounted within the housingabout the axis of the bores for rotational movement between the top andbottom walls, said lever member having a relatively large body portionlocated between the side walls and adjacent the top and bottom walls andhaving at least one dimension greater than the diameters of said bores;a pair of cylindrical shoulder portions integral with and on either sideof the large body portion, said shoulder being journaled within saidbores; a tang extending radially outward from the axis of the large bodyportion, said tang having a pair of faces converging outwardly from thelarge body portion toward an outer end and shaped to lie adjacent to andin substantially parallel relationship with the inside of either the topor bottom wall when the lever is rotated within the housing, said outerend of the tang being located adjacent the opening in the top wall inoperative position; and nut-gripping means projecTing outwardly of thehousing from a first one of said shoulder portions in co-axialrelationship with the bores whereby power hammer means operating throughthe opening in the top wall imparts unrestricted, high-energy turningforces to the gripping means, said bottom wall limiting movement of thelever member to a short rotational distance within the housingsubstantially equal to the angular relationship between the twoconverging faces of the tang and substantially absorbing the energy fromthe power hammer means transmitted to the lever member.
 2. The wrenchassembly of claim 1, including nut gripping means also projectingoutwardly of the housing from the second one of said shoulder portionsin co-axial relationship with said bores.
 3. The wrench assembly ofclaim 1, wherein said housing includes resilient means contiguous withat least a portion of the inside of said bottom that receives the tangand for absorbing at least some of the force of said tang as it moves inresponse to blows from the power hammer means.
 4. The wrench assembly ofclaim 1, wherein one of said side walls is removably affixed to thehousing and the lever member is reversible within the housing to permitthe assembly to be used in nut-tightening or loosening positions.
 5. Thewrench assembly of claim 1, including a second opening in the bottomwall of the housing opposite said first opening to permit the assemblyto be used in nut-tightening or loosening positions.
 6. The wrenchassembly of claim 1, wherein said nut-gripping means includes anextension integral with said first shoulder and having a nut-engagingport in its outer face.
 7. The wrench assembly of claim 1, wherein saidnut-gripping means includes an extension integral with said firstshoulder and having a cross section compatible with an annular socketwrench attachment.
 8. The wrench assembly of claim 1, further includinglocking means in said top wall opening for receiving and locking thepower hammer means in position.
 9. The wrench assembly of claim 8,wherein the locking means comprises a plurality of matable lugs on thepower hammer means and in the top wall opening.
 10. The wrench assemblyof claim 1, wherein the width of the tang occupies a substantial portionof the distance between the parallel side walls of the housing.
 11. Thewrench assembly of claim 1, including end walls to provide a completelyenclosed box-like housing.